1. Field
The present invention relates generally to a display device including a sealant and a manufacturing method thereof, and more particularly, to a display device and a manufacturing method thereof capable of reducing or preventing a Newton's ring phenomenon.
2. Description of the Related Art
A display device, such as a liquid crystal display (LCD), an organic light emitting diode (OLED) display, and an electrophoretic display, includes a field generating electrode and an electro-optical active layer. For example, the organic light emitting diode (OLED) display includes an organic light emitting layer as the electro-optical active layer. The field generating electrode is connected to a switching element, such as a thin film transistor, to receive a data signal, and the electro-optical active layer converts the data signal to an optical signal to display an image.
Among the display devices, because the organic light emitting diode (OLED) display, as a self-light emitting display, does not require a separate light source, its characteristics, in terms of power consumption, response speed, viewing angle, and contrast ratio, are excellent.
The organic light emitting diode (OLED) display may include a plurality of pixels such as red pixels, blue pixels, green pixels, or white pixels, and may express a full range of colors by combining the pixels. Each pixel includes an organic light emitting element and a plurality of thin film transistors for driving the organic light emitting element.
The light emitting element of the organic light emitting diode (OLED) display includes a pixel electrode, an opposed electrode, and a light emitting layer positioned between the two electrodes. One of the pixel electrode and the opposed electrode becomes an anode, and the other electrode becomes a cathode. An electron injected from the cathode and a hole injected from the anode are coupled with each other in the light emitting layer to form an exciton, and the exciton emits light while discharging energy. The opposed electrode is formed throughout a plurality of pixels to transfer a common voltage (e.g., a predetermined common voltage).
In a display device, in addition to the organic light emitting diode (OLED) display, when impurities such as moisture or oxygen flow or penetrate into the display device from an ambient environment, oxidization, exfoliation, and the like of the electrode may occur, and as a result, a lifespan of the device may be shortened or light emission efficiency may deteriorate, and effects such as deformation of an emitted color may occur.
Accordingly, when the display device is manufactured, sealing is performed so that an internal element is separated or protected from the outside to prevent impurities, such as moisture, from penetrating therein. The sealing method, in the case of the organic light emitting diode (OLED) display, may include, for example, a method of laminating a layer made of organic polymer such as polyester (PET) on a completed lower substrate, a method of forming a cover or a cap on an encapsulation substrate and sealing an edge of a cover substrate with a sealant, or the like. A frit having excellent moisture prevention characteristics may be included in the sealant, and an organic sealant and moisture absorbent may also be utilized.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.